efi.h 4.6 KB

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  1. /* SPDX-License-Identifier: GPL-2.0 */
  2. #ifndef _ASM_EFI_H
  3. #define _ASM_EFI_H
  4. #include <asm/boot.h>
  5. #include <asm/cpufeature.h>
  6. #include <asm/fpsimd.h>
  7. #include <asm/io.h>
  8. #include <asm/memory.h>
  9. #include <asm/mmu_context.h>
  10. #include <asm/neon.h>
  11. #include <asm/ptrace.h>
  12. #include <asm/tlbflush.h>
  13. #ifdef CONFIG_EFI
  14. extern void efi_init(void);
  15. bool efi_runtime_fixup_exception(struct pt_regs *regs, const char *msg);
  16. #else
  17. #define efi_init()
  18. static inline
  19. bool efi_runtime_fixup_exception(struct pt_regs *regs, const char *msg)
  20. {
  21. return false;
  22. }
  23. #endif
  24. int efi_create_mapping(struct mm_struct *mm, efi_memory_desc_t *md);
  25. int efi_set_mapping_permissions(struct mm_struct *mm, efi_memory_desc_t *md);
  26. #define arch_efi_call_virt_setup() \
  27. ({ \
  28. efi_virtmap_load(); \
  29. __efi_fpsimd_begin(); \
  30. raw_spin_lock(&efi_rt_lock); \
  31. })
  32. #undef arch_efi_call_virt
  33. #define arch_efi_call_virt(p, f, args...) \
  34. __efi_rt_asm_wrapper((p)->f, #f, args)
  35. #define arch_efi_call_virt_teardown() \
  36. ({ \
  37. raw_spin_unlock(&efi_rt_lock); \
  38. __efi_fpsimd_end(); \
  39. efi_virtmap_unload(); \
  40. })
  41. extern raw_spinlock_t efi_rt_lock;
  42. extern u64 *efi_rt_stack_top;
  43. efi_status_t __efi_rt_asm_wrapper(void *, const char *, ...);
  44. /*
  45. * efi_rt_stack_top[-1] contains the value the stack pointer had before
  46. * switching to the EFI runtime stack.
  47. */
  48. #define current_in_efi() \
  49. (!preemptible() && efi_rt_stack_top != NULL && \
  50. on_task_stack(current, READ_ONCE(efi_rt_stack_top[-1]), 1))
  51. #define ARCH_EFI_IRQ_FLAGS_MASK (PSR_D_BIT | PSR_A_BIT | PSR_I_BIT | PSR_F_BIT)
  52. /*
  53. * Even when Linux uses IRQ priorities for IRQ disabling, EFI does not.
  54. * And EFI shouldn't really play around with priority masking as it is not aware
  55. * which priorities the OS has assigned to its interrupts.
  56. */
  57. #define arch_efi_save_flags(state_flags) \
  58. ((void)((state_flags) = read_sysreg(daif)))
  59. #define arch_efi_restore_flags(state_flags) write_sysreg(state_flags, daif)
  60. /* arch specific definitions used by the stub code */
  61. /*
  62. * In some configurations (e.g. VMAP_STACK && 64K pages), stacks built into the
  63. * kernel need greater alignment than we require the segments to be padded to.
  64. */
  65. #define EFI_KIMG_ALIGN \
  66. (SEGMENT_ALIGN > THREAD_ALIGN ? SEGMENT_ALIGN : THREAD_ALIGN)
  67. /*
  68. * On arm64, we have to ensure that the initrd ends up in the linear region,
  69. * which is a 1 GB aligned region of size '1UL << (VA_BITS_MIN - 1)' that is
  70. * guaranteed to cover the kernel Image.
  71. *
  72. * Since the EFI stub is part of the kernel Image, we can relax the
  73. * usual requirements in Documentation/arm64/booting.rst, which still
  74. * apply to other bootloaders, and are required for some kernel
  75. * configurations.
  76. */
  77. static inline unsigned long efi_get_max_initrd_addr(unsigned long image_addr)
  78. {
  79. return (image_addr & ~(SZ_1G - 1UL)) + (1UL << (VA_BITS_MIN - 1));
  80. }
  81. #define alloc_screen_info(x...) &screen_info
  82. static inline void free_screen_info(struct screen_info *si)
  83. {
  84. }
  85. #define EFI_ALLOC_ALIGN SZ_64K
  86. /*
  87. * On ARM systems, virtually remapped UEFI runtime services are set up in two
  88. * distinct stages:
  89. * - The stub retrieves the final version of the memory map from UEFI, populates
  90. * the virt_addr fields and calls the SetVirtualAddressMap() [SVAM] runtime
  91. * service to communicate the new mapping to the firmware (Note that the new
  92. * mapping is not live at this time)
  93. * - During an early initcall(), the EFI system table is permanently remapped
  94. * and the virtual remapping of the UEFI Runtime Services regions is loaded
  95. * into a private set of page tables. If this all succeeds, the Runtime
  96. * Services are enabled and the EFI_RUNTIME_SERVICES bit set.
  97. */
  98. static inline void efi_set_pgd(struct mm_struct *mm)
  99. {
  100. __switch_mm(mm);
  101. if (system_uses_ttbr0_pan()) {
  102. if (mm != current->active_mm) {
  103. /*
  104. * Update the current thread's saved ttbr0 since it is
  105. * restored as part of a return from exception. Enable
  106. * access to the valid TTBR0_EL1 and invoke the errata
  107. * workaround directly since there is no return from
  108. * exception when invoking the EFI run-time services.
  109. */
  110. update_saved_ttbr0(current, mm);
  111. uaccess_ttbr0_enable();
  112. post_ttbr_update_workaround();
  113. } else {
  114. /*
  115. * Defer the switch to the current thread's TTBR0_EL1
  116. * until uaccess_enable(). Restore the current
  117. * thread's saved ttbr0 corresponding to its active_mm
  118. */
  119. uaccess_ttbr0_disable();
  120. update_saved_ttbr0(current, current->active_mm);
  121. }
  122. }
  123. }
  124. void efi_virtmap_load(void);
  125. void efi_virtmap_unload(void);
  126. static inline void efi_capsule_flush_cache_range(void *addr, int size)
  127. {
  128. dcache_clean_inval_poc((unsigned long)addr, (unsigned long)addr + size);
  129. }
  130. #endif /* _ASM_EFI_H */